This disclosure is based upon, and claims priority from, French Application No. 98/03472, filed Mar. 20, 1998, and International Application No. PCT/FR99/00558, filed Mar. 12, 1999, published by the International Bureau on Sep. 30, 1999, in a language other than English, the contents of which are incorporated herein by reference.
The present invention concerns the electronic labelling of products using labels each consisting of an electronic circuit disposed on a support adhering to the product to be identified. It concerns more particularly a system and method for temporarily or definitively inhibiting all or some functions of the label by means of a reading device.
More generally, the invention concerns a system and method for very rapidly effecting particular functions in contactless labels.
Products, in particular those for mass consumption, are identified by bar codes, which are read and analysed when they pass through the checkout so as to automatically determine their price by means of a data processing system. These bar codes are printed on the packaging of the product and define, for example, the name of the manufacturer and the type of product. These bar codes have a purely passive role and cannot be used for controlling the payment of the product, sell-by dates, the state of the stocks, theft, etc. Thus, in order to fulfil these new functions, it has been proposed to use active electronic labels consisting of a miniature electronic circuit or electronic chip carried by a support adhering to the product to be identified. These labels can be interrogated remotely by an interrogation and reading device and can respond by appropriate means.
These electronic labels record, for example, a number or code identifying the type of product such as an identical packet of rusks, an identical packet of butter, etc, as well as other codes indicating, for example, the sell-by date or the name of the manufacturer.
The so-called bottom of the range labels are generally produced by means of electronic circuits allowing only reading so that their content cannot change with a view to effecting certain functions which require writing to the label.
One of the functions which it would be advantageous to effect in an electronic label for reading alone is temporary or definitive inhibition in order to prevent use or reuse of the label or product when this is not authorised by the manufacturer. In addition, it would advantageous for this inhibition to be able to be total or partial.
One aim of the present invention is therefore to produce a system and to implement a method for temporarily or definitively inhibiting, partially or totally, electronic labels for contactless reading or for contactless reading/writing.
In more general terms, the invention aims to produce a system and to implement a method for permitting the use or not of certain functions of the electronic label for contactless reading or contactless reading/writing.
The invention therefore concerns a system for controlling particular functions in contactless electronic labels by means of a reading device transmitting, through a tuned-circuit antenna, signals at a carrier frequency F0, modulated by a modulator, the said transmitted signals being detected by a tuned-circuit antenna disposed on each electronic label, characterised in that:
the reading device also comprises a generator generating a plurality of sequences of pulses, the said pulses in each sequence being applied to the modulator in order to characteristically modify the signal at the carrier frequency,
the electronic label also comprises a circuit for detecting the pulses with a characteristic modulation and a circuit for interpreting the sequence of pulses, and
each sequence of pulses signifies a different action on the circuits of the electronic label.